1. Field of the Invention
The present invention relates to the field of liquid crystal displaying, and in particular to a slim frame backlight module.
2. The Related Arts
Liquid crystal display (LCD) has a variety of advantages, such as compact device size, low power consumption, and being free of radiation, and is thus widely used. Most of the LCDs that are currently available in the market are backlighting LCDs, which comprise a liquid crystal panel and a backlight module. The working principle of the liquid crystal panel is that liquid crystal molecules are interposed between two parallel glass substrates and a plurality of vertical and horizontal fine electrical wires is arranged between the two glass substrates, whereby the liquid crystal molecules are controlled to change direction by application of electricity in order to refract light emitting from the backlight module for generating images. Since the liquid crystal panel itself does not emit light, light must be provided by the backlight module in order to normally display images. Thus, the backlight module is one of the key components of an LCD. The backlight module can be classified as two types, namely side-edge backlight module and direct backlight module, according to the position where light gets incident. The direct backlight module arranges a light source, such as a cold cathode fluorescent lamp (CCFL) or a light-emitting diode (LED) at the back side of the liquid crystal panel to form a planar light source that directly provides lighting to the liquid crystal panel. The side-edge backlight module arranges a backlight source, such as an LED light bar based light source, at an edge of a back panel that is located rearward of one side of the liquid crystal panel. The LED light bar emits light that enters a light guide plate through a light incident face of the light guide plate and is projected out through a light exit face after being reflected and diffused to thereby form, after transmitting through a set of optic films, a planar light source to be provided to the liquid crystal panel.
With the development and popularity of liquid crystal display devices, it is increasingly demanded in the market that the thickness of the liquid crystal display panel is made thin and outer frame of the liquid crystal panel made slim. As shown in FIG. 1, a conventional bottom-incidence side-edge backlight module comprises a backplane 100, a bottom reflector plate 200 arranged inside the backplane 100, a light guide plate 300 disposed on the bottom reflector plate 200, a backlight source 400 arranged inside the backplane 100, and a side reflector plate 500 arranged above the backlight source 400. The side reflector plate 500 comprises an inclined reflection surface 502. The backlight source 400 is arranged below the reflection surface 502. The light guide plate 300 comprises a top surface 302, a bottom surface 304, and a plurality o side surfaces perpendicular to the top surface and the bottom surface. One of the side surfaces forms a light incident surface 306. The backlight source 400 emits light that is reflected by the reflection surface 502 toward the light incident surface 306, and then enters the light guide plate 300. Such a structure of backlight module provides an improved effect of frame slimming and a frame that is as slim as 4.3 mm can be realized. However, such a structure of backlight module has all the light reflected by the reflection surface 502 of the side reflector plate 500 before it enters the light guide plate 300. This, to some extents, limits the slimming of the backlight module.